Geologic, geochemical, and geophysical studies within the Raywood "Flat Roadless Areas, together with an investigation of mines and prospects within the further planning area, resulted in (1) identification of nonmetallic mineral resources at a marble mine in the further planning area and (2) recognition of a small area in the recommended wilderness that has moderate potential for base-metal resources. Except for these two areas of identified and suspected resources, we did not observe indications of resource potential elsewhere in the Raywood Flat Roadless Areas. The area having nonmetallic mineral resources is in the vicinity of the Mill Creek mine near the northeastern boundary of the further planning area (B5-187); there, we identified marginal reserves of marble suitable for the production of lime and construction stone. The reserves are marginal because of their remote location and poor accessibility. Geologic mapping did not reveal any additional marble occurrences within the study area. The area having moderate potential for base-metal resources forms a small zone in the eastern part of the recommended wilderness (A5-187). Within this zone, evidence provided by stream-sediment geochemistry suggests that crystalline bedrocks in several drainages contain concentrations of metallic elements. Because the terrain is inaccessible and covered with dense brush, most of the bedrock in the specific drainages containing the geochemical anomalies could not be examined. Thus, although we infer that mineral occurrences exist in the drainage basins, we have little data on which to base an estimate of their extent and quality. Locally, the crystalline rocks probably contain hydrothermal veins or disseminated occurrences where lead, copper, molybdenum, tin, cobalt, bismuth, and arsenic have been concentrated. However, the geochemical anomalies for these metals are small, and the stream drainages also are relatively small. Therefore, the inferred occurrences of metallic minerals probably are small scale, scattered, and low grade. There is only low probability that the inferred mineral occurrences are large scale.

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USGS1983

Mineral resource potential map of the Sugarloaf Roadless Area, San Bernardino County, California

Geologic, geochemical, and geophysical investigations and a survey of mines and prospects indicate that the Sugaloaf Roadless Area contains subeconomic graphite and magnesian marble resources. Parts of the area have a low potential for the occurrence of additional low-grade graphite resources, but there is no potential for additional magnesian marble resources within the roadless area. Sand, gravel, and construction stone other than carbonate rocks are found in the roadless area, but similar or better quality materials are abundant and more accessible outside the area. The roadless area has no identified energy mineral resources, but parts of the area have a low to moderate potential for low-grade uranium resources. There are no identified metallic mineral resources within the area, and there is no evidence of a potential for the occurrence of such resources. No previously unknown mineral occurrence was located during this study.

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USGS1982

Mineral resource potential map of the Whitewater Wilderness Study Area, Riverside and San Bernardino counties, California

Geological, geochemical, and geophysical evidence, together with a 'review of historical mining and prospecting activities, suggests that most of the Whitewater Wilderness Study Area has low potential for all types of mineral and energy resources- including precious and base metals, building stone and aggregate, fossil fuels, radioactive-mineral resources, and geothermal resources. One small area in the southern part of the study area shows evidence of gold and silver mineralization, and this locality has a low to moderate potential for the discovery of low-grade gold and silver resources.

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USGS1982

Mineral resource potential map of the Bighorn Mountains Wilderness Study Area (CDCA-217), San Bernardino County, California

Geological, geochemical, and geophysical evidence, together with a review of historical mining and prospecting activities, suggests that most of the Bighorn Mountains Wilderness Study Area has low potential for the discovery of all types of mineral and energy resources-including precious and base metals, building stone and aggregate, fossil fuels, radioactive-mineral resources, and geothermal resources. Low-grade mineralization has been documented in one small area near Rattlesnake Canyon, and this area has low to moderate potential for future small-scale exploration and development of precious and base metals. Thorium and uranium enrichment have been documented in two small areas in the eastern part of the wilderness study area; these two areas have low to moderate potential for future small-scale exploration and development of radioactive-mineral resources.

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USGS1982

Contour map showing minimum depth to ground water, upper Santa Ana River valley, California, 1973-1979

A contour map showing minimum depth to ground water from 1973 through 1979 was constructed for the upper Santa Ana River valley region. The map was prepared as an initial step in an ongoing liquefaction-potential study, but is not a liquefaction-hazard map. The contour map indicates where ground water shallower than 50 ft below land surface occurred at least once during the 1973-1979 period, and also indicates the probable future distribution of ground water shallower than 50 ft below land surface for periods when climatic conditions and water-management policies similar to those in the 1970's recur. This contour map does not show how the water table actually looked at any particular instant during the reporting period, nor does it show average or typical ground-water conditions during the reporting period. Instead, this map shows what the regional ground-water table would look like if the shallowest water level measured in each well during the 1973-1979 period is used as the basis for constructing a map of minimum depth to ground water. This map identifies twenty areas within the upper Santa Ana River valley where water levels in wells were shallower than 50 ft below land surface at least once during the period 1973-1979. In the greater Santa Ana River area, between the San Jacinto ground-water barrier and Prado flood-control dam, ground water was shallower than 50 ft below land surface intermittently throughout the 1973-1979 period. In this area, shallow water generally reflects shallow depths to impermeable bedrock and the ease and frequency with which ground water is replenished by natural and artificial recharge. Most of the other areas of shallow ground water identified on this map experienced pervasive shallow water levels only after mid-1977. Prior to mid-1977, ground water in these areas generally was deeper than 50 ft below land surface. During later parts of the 1973-1979 period, water tables rose mainly because of two factors: (1) wetter-than-normal winters in 1977-1978 and 19781979 contributed increased volumes of surface runoff and natural recharge in the upper Santa Ana River valley region; and (2) commencing in 1972, ground water in the Valley region has been replenished by artificial recharge of imported water derived from the California State Water Project. The accelerated natural and artificial recharge of ground water basins in 1977, 1978, and 1979 raised ground water tables throughout the Valley region. Water-level records more recent than September 1979 indicate that for most of the twenty areas of shallow ground water, water levels have remained shallower than 50 ft below land surface through December 1981. In some areas, water levels have risen even more. For example, in the San Bernardino area, rising water locally has invaded basements, undermined roadways, and affected foundation construction. Where post-1979 water levels have continued to rise, the areas underlain by shallow ground water have expanded and now are larger than the areas shown on the contour map of this report.

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USGS1982

Mineral resource potential map of the Bighorn Mountains Wilderness Study Area (CDCA-217), San Bernardino County, California

No abstract available.

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